The Russia tactics and strategies were fine during the war. All those scenes of seemingly sheer waste of human lives we saw on movies were desperate measures.
They were not ready to fight, due to different reasons, when the German attacked. The whole front collapsed, and the Germans were about to overrun their industrial and oil producing centers. Russia would be done for if they succeeded. Stalin himself issued an order, I read the English translation of that order, that any retreating unit the CO would be shot on spot and officers would be sent to the "punishment companies". They threw in human bodies to slow down the German momentum so that they could organize counter attack, just like what the USMC did during the early stage of the Korean war. Once the situation stabilized, the Russian brilliantly maneuvered around the Germans and had they trapped and their asses kicked.
OK, I have gone off the tangent here. Back to the original topic. All the surplus guns were shooting corrosive ammunition, including American arms. Most of them, at least one that appear in surplus market, seem to be doing just fine. The salt from corrosive primer would probably be a serious problem if the rifle were left uncleaned in high humidity. It is always a good practice to clean the rifle with water based solvent as soon as possible. No need to spend money on fancy products. Water will dissolve the salt. You need to flush it out, no just dissolve it, so use more. Oh, don't pee to your rifle.
-TL